Lifts are typically used to elevate heavy machinery or equipment to provide access to the bottom portions of such equipment or machinery. Such access may be necessary for repair or maintenance of such machinery or equipment. For example, lifts are typically used to elevate vehicles so that a mechanic servicing the vehicle can walk underneath the vehicle to work on the vehicle.
Lifts include a frame that moves vertically along one or multiple masts. The frame may include a pair of arms that extend outward. The arms are spaced apart so that a vehicle can be supported on the arms when the vehicle is lifted by the frame. The lift may include one or more masts that support the frame and the load of the vehicle being lifted by the frame. The mast(s) may be installed in the ground or be supported by a base.
Lifts typically operate by hydraulic power. Accordingly, hydraulic fluid is pressurized by one or a number of hydraulic pumps. The pressurized fluid then powers hydraulic actuators that can lift the vehicle with the frame. To maintain a vehicle in the elevated position, however, lifts have various locking systems to lock the frame to the mast or any other stationary structure of the lift. By locking the frame, the hydraulic actuator can only be used to lift the frame and does not have to operate to maintain the frame at a desired height. Additionally, the locking systems provide a safety feature in that to lower the frame, the locking system has to be unlocked.
Lifts typically include a locking system that can lock the frame to safely maintain the frame at a desired height. These locking systems may include several locks that have to be individually locked and unlocked by the operator of the lift. Each lock may have a unique vertical position along the mast that corresponds with a desired locking position. For example, a lift can include five locks that are positioned vertically along the mast such that each lock is spaced from an adjacent lock by a foot. Accordingly, the frame can be locked at five different heights relative to the mast, with each height being a foot apart from another lock. Accordingly, the number of locking positions of the frame and the distance between each locking position is defined by the number of locks and the distance between each lock, respectively. Additionally, in such lifts only one lock may be provided for each desired height. Therefore, in case of lock failure, the lift may drop and cause injury or death to any operator who may be standing near or beneath the lift.
Therefore, there exist a need for a locking system for lifts that provides safety in case of lock failure, a large number of close height adjustment increments for the locking of the frame, and ease of operation for the operator of the lift.